For several decades the Department of Energy (DOE), the Environmental Protection Agency (EPA) and other state agencies (e.g., Idaho Department of Environmental Quality) have been involved in clean up of radioactive waste, which has been generated and previously buried as part of nuclear research activities as well as from nuclear weapons production. Such radioactive waste may have resulted from a variety of waste streams, including process waste (e.g., sludge, graphite molds and fines, roaster oxides, and evaporator salts), equipment, and other waste incidental to nuclear research and nuclear weapons production. The radioactive waste may include contaminants such as transuranic isotopes, uranium, and various volatile organic compounds.
Contaminants from buried radioactive waste may leach into the soil and aquifer, which may be hazardous to human health, other life forms, and the environment. As part of the clean-up effort of such contaminants, the buried radioactive waste may be exhumed from pits, repackaged using more secure methods, and transported for further disposal and secured storage. For example, radioactive wastes classified as transuranic may be prepared and transported to the DOE's Waste Isolation Pilot Plant (WIPP) facility located near Carlsbad, N. Mex. for permanent disposal. Other classes of radioactive waste may be sent to other appropriate treatment or disposal facilities, such as Envirocare.
Buried radioactive waste may be excavated and packaged for certification, transport, and disposal. The location of the buried radioactive waste excavation may be referred to herein as a pit or a waste pit. Buried radioactive waste excavation has conventionally required packaging the excavated radioactive waste into drums. After packaging the radioactive waste into drums, the radioactive content of the radioactive waste may be characterized to determine if the packaged radioactive waste in the drums meet certification requirements and waste acceptance criteria for specific disposal facilities (e.g., WIPP, Envirocare), and also to ensure that safety regulations are met for transportation of the radioactive waste.
For example, for disposal of transuranic (TRU) wastes at the WIPP, the drums must be certified by the Environmental Protection Agency (EPA). The EPA must approve the execution of radioactive waste characterization activities before the drums are allowed to be shipped to WIPP for further disposal. A packaged drum may be rejected for certification at a waste disposal facility if the packaged drums are found to not meet appropriate criteria for acceptance to a disposal facility or for transportation. Once packaged, alterations to the radioactive waste may become more difficult, and therefore more costly to ensure acceptance by the disposal facility. For example, a drum that does not meet the acceptance criteria for the WIPP site may require further characterization and may be required to go through treatments, such as, incineration, compaction, thermal treatment, and/or vitrification before the drum can be certified for shipment and disposal at the WIPP site.
In other words, time and money may be wasted if the radioactive content of radioactive waste is too high (i.e., too hot), such that the drums fail to pass the official certification requirements for transportation and acceptance to disposal facilities. Another problem may arise if the radioactive content of the radioactive waste in the packaged drum is radioactive, yet not radioactive enough (i.e., too cool) for certain disposal facilities (e.g., WIPP). In that situation, it may be appropriate to return the radioactive waste to the waste pit, or if disposal is still required, the radioactive waste may be sent to a different disposal facility (e.g., Envirocare rather than WIPP).
Consequently, the inventors have appreciated that there is a need for an apparatus and method for a relatively rapid screening of radioactive waste, and more specifically transuranic waste, prior to packaging, certification, and disposal.